U.S. and Japanese officials say a U.S. Air Force helicopter has crashed on Japan's southern island of Okinawa.
Authorities say the crash took place Monday afternoon at a training ground near the U.S. Marine's Camp Hansen.
The U.S. Air Force says three of the four crew members on board the aircraft have been accounted for and are in stable condition. The remaining crew member has not been found.
The HH-60 helicopter was conducting a local training mission at the time of the crash. Authorities say they are investigating the incident.